Last week three gray whales were seen traveling together near Seattle, Washington. Their peaceful migration northwards was interrupted by a pod of “transient killer whales”, the type of orca that mainly eats other marine mammals. Groups of transient orcas are known to kill gray whales, especially calves. Encounters between transient killer whales and gray whales in Puget Sound have not been recorded before, even though both orcas and grays are commonly spotted on kayak tours in Puget Sound and the rest of the Salish Sea.

A Seattle whale-watching tour spotted two adult gray whales traveling with a younger gray, and three adult transient orcas with an older calf. The encounter began when the male orca surfaced right alongside the grays after a long dive. A lot of splashing and churning ensued with slicing fins and waving flukes visible. It appeared that the two adult gray whales took a defensive stance with one on each side of the younger gray whale. The gray whales refused to move while the killer whales bumped into them.

The powerful slashing flukes of a 40-ton gray whale can severely injure or kill an orca whale. And these transient orcas apparently decided that the cornered gray whales were going to be too dangerous. The orcas broke off the attack before any blood was shed, and the whole event seemed like a test of resolve that the gray whales passed. After waiting several minutes to be sure it wasn’t a ruse, the gray whales eventually resumed their normal activities. The abundant harbor seals in Puget Sound are the transient killer whales favorite food, perhaps because they pose much less risk to the hunters of getting injured.